This invention is in the field of lubricating devices. Various vehicles including automobiles and motorcycles are supported for movement by wheels rotatably mounted upon axles. Each wheel typically includes a hub with a pair of rolling contact bearings through which the axle projects. Normally, each bearing is retained within the hub by means of a removable spring clamp. In order to effectively lubricate the bearings, the clamps must first be removed and then the bearings physically removed from the hub. The clamps frequently are difficult to remove and in fact break in certain instances. Therefore, it is desirable to lubricate the bearings while mounted within the hub. Several devices have been designed to achieve this objective. For example, the U.S. Pat. No. 2,160,214 issued to Jackson discloses a pair of mutually opposed cones which project partially into the hub from opposite sides being threadedly mounted on a perforated tube through which grease flows to the bearings. Another device for flushing and lubricating a roller bearing is shown in U.S. Pat. No. 2,210,478 issued to Berg. Various types of grease guns and lubricators which use a number of different types of movable components have been devised such as shown in U.S. Pat. Nos. 3,158,226 issued to Williamson, 3,717,222 issued to Moline and 4,113,059 issued to Markovski.
The prior devices which include movable parts, such as spring-biased pistons for injecting the lubricating medium, or other lubricators which require assembly and disassembly of components in order to insert the lubricator through the hub, are particularly troublesome since old grease and dirt accumulate on the various components and threaded surfaces necessitating frequent cleaning of the lubricators for proper use. Disclosed herein is a new and improved lubricator which may be extended through the hub while the bearings are in place and which does not require assembly or disassembly of various lubricator components prior to each lubrication.